package os

import (
	"bytes"
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"testing"

	"github.com/stretchr/testify/require"
)

func TestCopyFile(t *testing.T) {
	tmpfile, err := ioutil.TempFile("", "example")
	if err != nil {
		t.Fatal(err)
	}
	defer os.Remove(tmpfile.Name())
	content := []byte("hello world")
	if _, err := tmpfile.Write(content); err != nil {
		t.Fatal(err)
	}

	copyfile := fmt.Sprintf("%s.copy", tmpfile.Name())
	if err := CopyFile(tmpfile.Name(), copyfile); err != nil {
		t.Fatal(err)
	}
	if _, err := os.Stat(copyfile); os.IsNotExist(err) {
		t.Fatal("copy should exist")
	}
	data, err := ioutil.ReadFile(copyfile)
	if err != nil {
		t.Fatal(err)
	}
	if !bytes.Equal(data, content) {
		t.Fatalf("copy file content differs: expected %v, got %v", content, data)
	}
	os.Remove(copyfile)
}

func TestEnsureDir(t *testing.T) {
	tmp, err := ioutil.TempDir("", "ensure-dir")
	require.NoError(t, err)
	defer os.RemoveAll(tmp)

	// Should be possible to create a new directory.
	err = EnsureDir(filepath.Join(tmp, "dir"), 0755)
	require.NoError(t, err)
	require.DirExists(t, filepath.Join(tmp, "dir"))

	// Should succeed on existing directory.
	err = EnsureDir(filepath.Join(tmp, "dir"), 0755)
	require.NoError(t, err)

	// Should fail on file.
	err = ioutil.WriteFile(filepath.Join(tmp, "file"), []byte{}, 0644)
	require.NoError(t, err)
	err = EnsureDir(filepath.Join(tmp, "file"), 0755)
	require.Error(t, err)

	// Should allow symlink to dir.
	err = os.Symlink(filepath.Join(tmp, "dir"), filepath.Join(tmp, "linkdir"))
	require.NoError(t, err)
	err = EnsureDir(filepath.Join(tmp, "linkdir"), 0755)
	require.NoError(t, err)

	// Should error on symlink to file.
	err = os.Symlink(filepath.Join(tmp, "file"), filepath.Join(tmp, "linkfile"))
	require.NoError(t, err)
	err = EnsureDir(filepath.Join(tmp, "linkfile"), 0755)
	require.Error(t, err)
}